'Vampire' killer

Such equipment, from televisions to hi-fis, can increase an average household's annual power bill by $100, according to Rachel Turner, the creator of the Standby Monster.

Her approach is to scare users into switching off devices with a pair of sticky-backed lenses that fit over the standby light and turn it into a pair of glowing, sinister eyes.

(Image: Greener Gadgets)

Command central

Frog Design's central kill switch is also designed to tackle energy vampires.

Wireless units called WattBlocks are fitted between the wall sockets and plugs of devices, making it possible to switch them all off in an instant using the master step switch (left).

(Image: Greener Gadgets)

Electricity alerts

Overall winner Tweet-a-Watt takes power management online. Limor Fried of Adafruit Industries and Phillip Torrone of MAKE magazine added a wireless transmitter (left) to a power meter creating a gadget that transmits daily summaries of energy consumption to the user's Twitter account.

Another short-listed design – Bware by Ariel Drach (right) – promises to do the same thing for water consumption.

Blinding light

The Blight blinds were designed by Vincent Gerkens, who says that because people adjust Venetian blinds throughout the day to maximise the amount of sunlight they block out, his design catches much of the available sunlight.

When darkness falls, energy collected in a battery is used to power an electroluminescent foil built into the blinds, which lights the room.

(Image: Greener Gadgets)

Café culture

Office printers consume energy and may even pose a health risk. But the hand-powered RITI Printer, designed by Jeon Hwan Ju, is different.

Power comes from the user, who has to pull the printer head back and forth as the paper is pulled through. Cleverly, the printer also does away with expensive ink cartridges, instead making use of waste coffee.